The rib is about .230 high. If your web is 3/16 thick, that is .1875, so the rib is about .040 high at the groove. (You said 1/16 to 3/32" high, a lot worse). You could file it down for the last 4 or 5 inches to get the rod to go in. But- the underlugs may project into the rod hole and the rod likely will hit them. I file the underlugs down to avoid this. You want the entry pipe barrel and nose cap groove and rib to be the same elevation. Or you could drill the rod hole larger so your 7/16 rod will clear the underlugs. Likely you have Track's Hawken entry pipe RP-Hawk-E-7-I with a lot of hump, not like on any original Hawken I have seen. The correct one is RP-Hawk-TE-7-I, with less hump, as on the Bridger and Kit Carson Hawkens. You could glue a snug fitting dowel into the rod hole and redrill it at the correct level. Fit the nose cap first. Then drill through the pipes for the rod hole. You could super glue the rib on temporarily for the alignment of the drill rod. I drill within a 1/4" of the tang bolt for the longest rod I can get. The correct entry pjpe will have to be inlet and moved back a little, which is easy to do. In fitting the nose cap, allow for the shorter entry pipe, if you change it. You have the entry pipe inleted, you could refit it "higher" to move it into alignment with your rib and nosecap grooves. Glue a shim under the skirt and sides of the barrel if needed there. A Hawken rifle would be a helluva lot easier to build if the parts and inletting were correct. Usually the tang needs bending and so does the trigger plate.
